Releasable servo writing fixture connector

Abstract

Releasable connectors are disclosed for attaching a servo writing fixture to a head transducer assembly to facilitate writing servo information on a servo surface of a rigid disk drive. One connector includes a body for support and attachment of the fixture and an engagement collet for attachment to the top arm of the transducer arm assembly. The engagement collet has a spring operated internal mandrel which disengages the collet from the transducer assembly. Alignment is accomplished with a registration pin that attaches to the top arm of the arm assembly. The second connector includes two parts that are hinge connected in the middle and spring biased apart at the top to form a clamping mechanism. The completed hinged connector defines three leg extensions for attachment to the side of the top arm of the arm assembly and alignment in an opening in the top arm of the arm assembly. Release of the second connector occurs upon compression of the spring. The invention finds special application for attaching and aligning a laser beam retroreflector to the arm assembly to be used in conjunction with a laser interferometer to accomplish servo writing operations on a plurality of disks. The invention is adaptable for use with robotics.

I claim: 
     
       1. An apparatus for temporarily attaching a servo writing tool to a head transducer arm assembly of a rigid disk drive, the arm assembly defining a topmost arm having a plurality of attachment locations, comprising: a body for supporting the tool in prearranged alignment;   releasable engagement means for engaging the topmost arm at the attachment locations; and   registration means for alignment registration of the body.   
     
     
       2. The apparatus set forth in claim 1 wherein the tool is affixed to and supported by the body. 
     
     
       3. The apparatus set forth in claim 2 wherein the servo writing tool is a laser beam retroreflector for reflecting a servo track alignment laser interferometer. 
     
     
       4. The apparatus set forth in claim 1 wherein the attachment locations are openings vertically extending through the topmost arm, and wherein the engagement means is an engagement collet for seating in one of the openings. 
     
     
       5. The apparatus set forth in claim 4 wherein the engagement collet comprises a cylindrical outer portion defining a series of radial teeth and a cylindrical internal collet release member. 
     
     
       6. The apparatus set forth in claim 5 wherein the collet release member is mandrel having a threaded top. 
     
     
       7. The apparatus set forth in claim 6 wherein the mandrel is operated by a spring operated nut. 
     
     
       8. The apparatus set forth in claim 7 wherein the registration means is a pin for seating in the other of the openings. 
     
     
       9. The apparatus set forth in claim 4 wherein the registration means is a pin for seating in the other of the openings. 
     
     
       10. The apparatus set forth in claim 1 wherein the body comprises a first part and a second part hinged to the first part by transverse, centrally disposed hinge pin means; the releasable engagement means comprises downwardly extending, oppositely facing leg portions formed on the parts; releasable bias spring means for biasing the leg portions into engagement contact with the topmost arm; and the registration means comprises structure of the topmost arm adapted to receive and align at least one of the leg portions. 
     
     
       11. The apparatus set forth in claim 10 wherein the tool is affixed to and supported by the body. 
     
     
       12. The apparatus set forth in claim 11 wherein the servo writing tool is a laser beam retroreflector for reflecting a servo track alignment laser interferometer. 
     
     
       13. The apparatus set forth in claim 10 wherein the leg portion of the first part comprises a plurality of legs with notched feet for engagement with a side of the topmost arm of the arm assembly; and wherein the registration means comprises structure on the side adapted to mate with the notched feet. 
     
     
       14. The apparatus set forth in claim 13 wherein the registration means further comprises a single leg with a foot formed on the second part for engagement within an opening formed in the topmost arm of the arm assembly. 
     
     
       15. The apparatus set forth in claim 10 wherein the first part further comprises a shelf for attachment of the retroreflector. 
     
     
       16. An apparatus for temporarily attaching a servo writing tool to a head transducer arm assembly of a rigid disk drive, the arm assembly defining a topmost arm having at least two openings vertically extending therethrough, comprising: a body shaped octagonally at one end and having a housing at the opposite end for holding the servo writing tool;   the octagonal end of the body having an aperture extending vertically through the body;   the body having a releasable engagement collet within the aperture for engaging a first opening of the topmost arm, the engagement collet being cylindrically shaped and defining eight teeth and containing an internal mandrel with a threaded top;   a spring operated nut within the first aperture for operation of the engagement collet, the nut engaged with two sets of belleville washers that define the maximum depth of vertical movement of the communicating mandrel;   the servo writing tool holding end of the body having a registration pin for registration in a second arm assembly opening when the collet is engaged.   
     
     
       17. An apparatus for temporarily attaching a retroreflector to a head transducer arm assembly of a rigid disk drive, the arm assembly defining a topmost arm having sides and at least two openings vertically extending therethrough, comprising: a body having a first part and a second part, each part having an arm with an axially aligned perforation therethrough, the arm of the second part defining a U-shape that surrounds the arm of the first part;   a hinge pin for insertion through both arm perforations to connect the first and second parts in a hinge formation;   a spring connected to the first and second parts for biasing the two parts, compression of the spring operating the hinge and releasing the apparatus from the arm assembly;   the first part further having a single leg for attachment within an opening in the top arm of the arm assembly, the single leg aligning the retroreflector and attaching to the arm assembly by a foot;   the second part having two legs with notched feet for attachment to the side of the top arm assembly; and   the second part further having an extension for attachment of the retroreflector.   
     
     
       18. The apparatus set forth in claim 17 wherein the bias means biases the leg portions together.